# Blocks and Springs

1. Nov 10, 2004

### Soaring Crane

There is a spring on a ledge that is 15 m above the ground. It is compressed 0.5 m by a block of 3 kg, and its spring constant is 15 N/m. I'm not certain of the exact wording, but somehow the compressed string (with the block) is the horizontal length of the ledge.

Now in this scenario, the block as a result of the spring falls from the ledge "vertically" to the ground and then rolls a distance D from the base of the ledge.

a. Find the initial elastic potential energy.

b. Find the initial gravitational potential energy of the block.

c. Find the gravitational potential energy of the block as it hits the ground.

d. Find the block's velocity before hitting the ground.

e. Find D.

Diagram:

/\/\/\/\|_|
------------
________|
________|
________|15 m
________|_______D_______

/\/\spring
|__|block

Any hints or pointers, aside from general formulas like kx^2/2 and and mgh, are appreciated.

Last edited: Nov 10, 2004
2. Nov 10, 2004

### Parth Dave

You're gonna have to show us what you did. It's hard to pick out where you are having trouble if we don't know what you did. Part (a) looks like you just have to take the numbers you are given and plug them into a formula.

3. Nov 10, 2004

a. 1.875 J
b. 75 J
c. 0 J
d. 2.7 m/s
e. 4.7 m